With the rapid development of IP (Internet Protocol) applications, traffic of an IP network, especially a backbone network, grows rapidly. At present, the IP network is generally formed by a router and an optical transmission device. At a packet level, forwarding paths of IP packets are all based on IP routing paths, therefore, a forwarding path of an IP packet is fixed as long as IP routing is unchanged. However, an IP network load is changing. If the forwarding path of the IP packet cannot be adjusted dynamically according to the load, an overall load of the network is unbalanced, so that the network is partially congested, a utilization rate of network capacity is low, and quality of service of the network is affected.